<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>默认字体大小</title>
<style type="text/css">
body { font-size: 62.5%; padding: 0px; margin: 0px;  } 
#div1 { font-size: 20px; width: 1200px; border: 1px solid #ddd; }
#div2 { font-size: 2em; width: 60em; border: .05em solid #ddd; margin-top: 30px; }
</style>
</head>
<body>
<div id="div1">默认字体大小</div>
<div id="div2">默认字体大小</div>
</body>
<script type="text/javascript" src="statics/common/js/md.zepto.js"></script>
<script type="text/javascript">
var style = document.body.currentStyle || document.defaultView.getComputedStyle(document.body, '')
alert(style.fontSize);
var div = document.getElementById('div');
//alert(div.style.fontSize);
//alert($("#div").css("font-size"));
//alert($("#div").css("color"));
computedStyle = getComputedStyle(div, '')
//alert(computedStyle.getPropertyValue("font-size"))
</script>
</html>